Felty's syndrome: granulocyte-bound immunoglobulin G and splenectomy

A quantitative antiglobulin consumption technique was used to measure immunoglobulin G (IgG) present on human granulocytes. Granulocytes from 50 normal subjects had less than 20 X 10(-14) g IgG per cell. Patients with granulocytopenia due to bone-marrow failure, patients with IgG multiple myeloma, patients with splenomegaly, and patients with rheumatoid arthritis without granulocytopenia had granulocyte-bound IgG within the range of normal. Four patients with rheumatoid arthritis, splenomegaly, and severe granulocytopenia (Felty's syndrome) had granulocyte-bound IgG between 30 and 220 X 10(-14) g IgG per cell. One of these patients underwent splenectomy, after which his granulocyte-bound IgG fell to normal. Seven additional patients with Felty's syndrome who had previously undergone splenectomy had normal levels of granulocyte-bound IgG. Thus quantitation of granulocyte-bound IgG appears to be useful in defining patients with immunologically mediated granulocytopenia. Studies of patients with Felty's syndrome who have undergone splenectomy suggest that the spleen may produce this neutrophile-bound immunoglobulin.